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st link v2 red led is on

osman2
Associate II

Hello
The LED on the top link is red. Is it a problem with the connection or the driver? I can't figure it out. Can you help me?

14 REPLIES 14

Please see this for how to capture a screenshot - far better than photographing the screen!

https://www.techrepublic.com/article/how-to-take-screenshots-in-windows-10/

 

The pop-up message is telling you that it can't detect any connected STM32 target device:

AndrewNeil_0-1730973673941.png

 

The log shows you that the target supply voltage is only 0.46V

AndrewNeil_2-1730973783592.png

Your Target can't be running with less than half a volt supply!

You need to fix the power supply on the target.

Note that the ST-Link/V2 does not supply power to the target.

 

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

The meaning of the LED is described in the User Manual:

AndrewNeil_3-1730974074858.png

https://www.st.com/resource/en/user_manual/um1075-stlinkv2-incircuit-debuggerprogrammer-for-stm8-and-stm32-stmicroelectronics.pdf#page=15

 

So the PC is communicating with the ST-Link, but the ST-Link has not yet had any communication - successful or otherwise - with the Target.

As described in my previous post, your ST-Link can't communicate with your Target because the Target has no power.

The ST-Link can't distinguish this condition from simply having no target connected at all.

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

I know how to take a screenshot but the computer I took it on didn't have internet so I took it with my phone

Should I connect another device to the st-link instead of the computer's usb port?
Thank you for your interest

I apologize, but I plugged it into other ports, but for some reason the voltage does not increase and stays at 0.46


@osman2 wrote:

I plugged it into other ports, but for some reason the voltage does not increase and stays at 0.46


Again, the ST-Link does not supply power to the Target.

Your screenshot shows that the PC is communicating fine with the ST-Link;  there is no problem there - no need to try different USB ports.

The problem is that your Target is not powered.

How are you trying to power the Target?

What Target is it?

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

dear andrew
no cable is currently connected to the st link- cn3 socket

You don't have anything connecting to Pin 1 which should be the VTarget voltage to power the interface buffers on the ST-LINK side

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Up vote any posts that you find helpful, it shows what's working..

Do I need to give 3.3v from pin1 of the cn3 socket?


@osman2 wrote:

no cable is currently connected to the st link- cn3 socket


That's where you would connect the cable from the ST-Link to you Target.

If you have nothing connected there then, clearly, the ST-Link will not see any Target connected!

In this situation, the Red LED illuminated is the expected condition - as explained earlier.

 

AndrewNeil_1-1730980089721.png

Have you studied the User Manual?

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.